1. Field of the Invention
The present invention relates to a method for verification of the constituent chemical compounds of a process stream, that is, for verifying that a chemical substance that should or should not be present in a process stream is in fact present or not present, respectively. In particular, the invention relates to verifying the presence of a chemical warfare agent to be destroyed in a destruction facility, and verifying the absence of such substances in a facility not intended for producing chemical warfare agents. The United States Government has fights in this invention pursuant to Contract No. DE-AC09-89SR18035 between the U.S. Department of Energy and Westinghouse Savannah River Company.
2. Discussion of Background:
The U.S. and other nations have large stockpiles of chemical warfare agents, including the so-called "nerve gases": HD (mustard gas), GA (tabun), GB (sarin), etc. Some stocks are outdated and must be destroyed; others are scheduled for destruction to comply with treaty requirements. Agents shipped to a destruction facility could conceivably be diverted and replaced by simulants or surrogates. Therefore, it is important to verify that "declared" agents, that is, agents for which claims are made that they are a constituent being introduced into a destruction facility, are actually introduced and are being destroyed. On-site inspection may be difficult to arrange and only partially effective. Furthermore, nerve gas agents are lethal in extremely small quantities, so any testing procedure must minimize the possibility of human exposure.
From time to time, other hazardous substances that present verification problems may be scheduled for destruction. Such substances include common pesticides and insecticides, and hazardous byproducts from industrial processes.
Related to the problem of verifying the destruction of chemical warfare agents, is the problem of verifying that such agents are not being produced. Common phosphene-based pesticides are chemically related to nerve gas agents and are manufactured by similar processes. For example, the pesticide diazinon is similar to the nerve gas agent GB (sarin). A diazinon manufacturing facility can be converted to GB production in a few weeks. In some cases, it is important to verify that a legitimate pesticide plant is not being used to manufacture nerve gas agents. Here, rather than the absence of a hazardous substance among the constituents that might signal a diversion, it is the presence of a constituent of a hazardous substance that might signal that hazardous substances are being made.
It is well known to analyze the exhaust gases of an incinerator as a check on its efficiency. For example, Schultz (U.S. Pat. No. 4,666,696) describes a process for the destruction of nerve gases and other cholinesterase inhibitors by molten metal reduction in a furnace. The exhaust gases are analyzed for the presence of the agent(s) being destroyed and returned to the furnace if not free of the agents. However, verifying the identity of a substance just before it is introduced into an incinerator or other destruction facility has not been done.
There is a need for a method for verifying the identity of a substance before it is introduced into a destruction facility, or, alternatively, to verify that a substance is absent from a production facility.